Nuclear factor Nrf2 promotes glycosidase OGG1 expression by activating the AKT pathway to enhance leukemia cell resistance to cytarabine

Abstract

Chemotherapy resistance is the dominant challenge in the treatment of acute myeloid leukemia (AML). Nuclear factor E2–related factor 2 (Nrf2) exerts a vital function in drug resistance of many tumors. Nevertheless, the potential molecular mechanism of Nrf2 regulating the base excision repair pathway that mediates AML chemotherapy resistance remains unclear. Here, in clinical samples, we found that the high expression of Nrf2 and base excision repair pathway gene encoding 8-hydroxyguanine DNA glycosidase (OGG1) was associated with AML disease progression. In vitro, Nrf2 and OGG1 were highly expressed in drug-resistant leukemia cells. Upregulation of Nrf2 in leukemia cells by lentivirus transfection could decrease the sensitivity of leukemia cells to cytarabine, whereas downregulation of Nrf2 in drug-resistant cells could enhance leukemia cell chemosensitivity. Meanwhile, we found that Nrf2 could positively regulate OGG1 expression in leukemia cells. Our chromatin immunoprecipitation assay revealed that Nrf2 could bind to the promoter of OGG1. Furthermore, the use of OGG1 inhibitor TH5487 could partially reverse the inhibitory effect of upregulated Nrf2 on leukemia cell apoptosis. In vivo, downregulation of Nrf2 could increase the sensitivity of leukemia cell to cytarabine and decrease OGG1 expression. Mechanistically, Nrf2–OGG1 axis–mediated AML resistance might be achieved by activating the AKT signaling pathway to regulate downstream apoptotic proteins. Thus, this study reveals a novel mechanism of Nrf2-promoting drug resistance in leukemia, which may provide a potential therapeutic target for the treatment of drug-resistant/refractory leukemia. Chemotherapy resistance is the dominant challenge in the treatment of acute myeloid leukemia (AML). Nuclear factor E2–related factor 2 (Nrf2) exerts a vital function in drug resistance of many tumors. Nevertheless, the potential molecular mechanism of Nrf2 regulating the base excision repair pathway that mediates AML chemotherapy resistance remains unclear. Here, in clinical samples, we found that the high expression of Nrf2 and base excision repair pathway gene encoding 8-hydroxyguanine DNA glycosidase (OGG1) was associated with AML disease progression. In vitro, Nrf2 and OGG1 were highly expressed in drug-resistant leukemia cells. Upregulation of Nrf2 in leukemia cells by lentivirus transfection could decrease the sensitivity of leukemia cells to cytarabine, whereas downregulation of Nrf2 in drug-resistant cells could enhance leukemia cell chemosensitivity. Meanwhile, we found that Nrf2 could positively regulate OGG1 expression in leukemia cells. Our chromatin immunoprecipitation assay revealed that Nrf2 could bind to the promoter of OGG1. Furthermore, the use of OGG1 inhibitor TH5487 could partially reverse the inhibitory effect of upregulated Nrf2 on leukemia cell apoptosis. In vivo, downregulation of Nrf2 could increase the sensitivity of leukemia cell to cytarabine and decrease OGG1 expression. Mechanistically, Nrf2–OGG1 axis–mediated AML resistance might be achieved by activating the AKT signaling pathway to regulate downstream apoptotic proteins. Thus, this study reveals a novel mechanism of Nrf2-promoting drug resistance in leukemia, which may provide a potential therapeutic target for the treatment of drug-resistant/refractory leukemia. Acute myeloid leukemia (AML) refers to a malignant tumor with uncontrolled proliferation of immature myeloid cells. The standard induction chemotherapy for AML is “3 + 7” regimen, that is, 3-day anthracycline + 7-day cytarabine (Ara-C) for remission. After chemotherapeutic treatment, only a few AML patients survived for over 5 years, and most patients died of relapse or some related complications. Therefore, chemotherapy resistance has turned into a leading challenge in AML treatment. Studies have proved that AML has varieties of drug resistance mechanisms, including adaptive cytoprotection mechanism (1Lam S.S.Y. Leung A.Y.H. Overcoming resistance to FLT3 inhibitors in the treatment of FLT3-mutated AML.Int. J. Mol. Sci. 2020; 21: 1537Crossref PubMed Scopus (32) Google Scholar), tumor microenvironment protection (2Ganesan S. Mathews V. Vyas N. Microenvironment and drug resistance in acute myeloid leukemia: do we know enough?.Int. J. Cancer. 2022; 150: 1401-1411Crossref PubMed Scopus (5) Google Scholar, 3Menter T. Tzankov A. Tumor microenvironment in acute myeloid leukemia: adjusting Niches.Front. Immunol. 2022; 13: 811144Crossref PubMed Scopus (13) Google Scholar), autophagy (4Joffre C. Ducau C. Poillet-Perez L. Courdy C. Mansat-De Mas V. Autophagy a close relative of AML biology.Biology (Basel). 2021; 10: 552PubMed Google Scholar), and epigenetic mutation (5Yun H. Narayan N. Vohra S. Giotopoulos G. Mupo A. 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Gundamaraju R. et al.Re-establishing the comprehension of phytomedicine and nanomedicine in inflammation-mediated cancer signaling.Semin. Cancer Biol. 2022; 86: 1086-1104Crossref PubMed Scopus (19) Google Scholar). In the DDR pathway, BER is responsible for repairing most DNA damage and exerts a vital role in the maintenance of gene integrity (8Ouyang Y. Liu Y. Deng Y. He H. Huang J. Ma C. et al.Recent advances in biosensor for DNA glycosylase activity detection.Talanta. 2022; 239: 123144Crossref PubMed Scopus (3) Google Scholar), which is tightly associated with tumor relapse and drug resistance (9Cho H.Y. Wang W. Jhaveri N. Lee D.J. Sharma N. Dubeau L. et al.NEO212, temozolomide conjugated to perillyl alcohol, is a novel drug for effective treatment of a broad range of temozolomide-resistant gliomas.Mol. Cancer Ther. 2014; 13: 2004-2017Crossref PubMed Scopus (48) Google Scholar). Therefore, investigating the molecular mechanism of BER pathway and drug resistance is a crucial strategy to overcome clinical relapse and chemotherapy resistance. Nuclear factor E2–related factor 2 (Nrf2, also known as NFE2L2) is a key factor in antioxidant stress system. Its deletion or activation will directly influence the balance of intracellular redox (10Smolkova K. Miko E. Kovacs T. Leguina-Ruzzi A. Sipos A. Bai P. Nuclear factor erythroid 2-related factor 2 in regulating cancer metabolism.Antioxid. Redox Signal. 2020; 33: 966-997Crossref PubMed Scopus (40) Google Scholar). Based on normal physiological situations, Nrf2 binds to Kelch-like ECH-related protein 1 (Keap1), existing inactively in the cytoplasm. 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R. et and expression in an disease PubMed Scopus Google Scholar). In the BER pathway, OGG1 is an which is mainly responsible for and as to the integrity of function S. X. M. between and OGG1 repair of base and is by 2020; PubMed Scopus Google Scholar, Wang H. W. W. Wang H. et of a for DNA glycosylase 2021; PubMed Scopus Google Scholar). OGG1 is to the proliferation of tumor tightly in the and of multiple cancers C. M. G. high proliferation and apoptotic in the of of the in J. Cancer. PubMed Scopus Google Scholar, K. Y. Y. DNA repair gene and and cancer in a J. Oncol. PubMed Scopus Google Scholar). In leukemia with high OGG1 expression has a poor prognosis and a of relapse K. R. A. OGG1 is a novel in acute myeloid PubMed Scopus Google Scholar). The damage of cells with is achieved by the nuclear expression of Nrf2 and OGG1 expression of BER pathway gene J. DNA glycosylase 1 of and protein in PubMed Scopus Google Scholar). In addition, has that the inhibition of DNA damage by in cancer is related to the of OGG1 expression by Nrf2 A. N.K. of OGG1 NRF2 induction is associated with inhibition of DNA damage in Cancer. 13: PubMed Scopus Google Scholar). has Nrf2 is in regulating BER pathway genes leading to drug resistance in The to the function of Nrf2 and BER pathway OGG1 in AML resistance. 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Chen W. et of by acute myeloid leukemia to 2021; PubMed Scopus (12) Google Scholar). Nrf2 expression is tightly associated with the chemotherapy resistance of multiple tumors X. Y. Zhou Y. Hu W. C. Q. et the of NRF2 carcinoma cells to Biol. 2021; PubMed Scopus Google Scholar, M. A. C. G. S. of Nrf2 and by and in cancer Biol. Med. 2021; PubMed Scopus Google Scholar, S. and cancer drug 2021; PubMed Scopus (48) Google Scholar). BER is the of DDR mechanism L. E. base excision repair in chromatin 2020; PubMed Google Scholar). The of BER pathway to temozolomide in malignant tumors (9Cho H.Y. Wang W. Jhaveri N. Lee D.J. Sharma N. Dubeau L. et al.NEO212, temozolomide conjugated to perillyl alcohol, is a novel drug for effective treatment of a broad range of temozolomide-resistant gliomas.Mol. Cancer Ther. 2014; 13: 2004-2017Crossref PubMed Scopus (48) Google Scholar). Therefore, inhibition of in BER pathway may certain In AML patients with high expression of OGG1 have poor K. R. A. OGG1 is a novel in acute myeloid PubMed Scopus Google Scholar). Furthermore, OGG1 is an target for leukemia cells T. C. A. K. et OGG1 cancer cell proliferation by 2020; PubMed Scopus Google Scholar). with AML cells with high OGG1 cells were to N. S.K. in acute myeloid leukemia Sci. S. A. 2021; Scopus Google Scholar). In addition, OGG1 gene can also increase the of relapse in patients AML N. T. N. T. Y. A. et between OGG1 and relapse in acute myeloid J. PubMed Scopus Google Scholar). The that Nrf2 and OGG1 a role in AML relapse and drug its mechanism remains unclear. the we that of Nrf2 the role of OGG1 expression in drug resistance of In the of Nrf2 and OGG1 in AML were in normal samples, which were by clinical and drug-resistant cell that Nrf2 and OGG1 might be potential drug resistance genes in the relationship between Nrf2 and we upregulated the expression of Nrf2 in AML cell and Nrf2 in drug-resistant AML cell is that Nrf2 could positively regulate the expression of OGG1. In addition, we also that the activity of OGG1 and the expression of of Meanwhile, the revealed that the apoptotic of upregulated Nrf2 cells whereas Nrf2 that Nrf2 the sensitivity of AML cells to chemotherapeutic drug has revealed that Nrf2 activation its to the OGG1 promoter a role in cells A. N.K. of OGG1 NRF2 induction is associated with inhibition of DNA damage in Cancer. 13: PubMed Scopus Google Scholar, P. H. in and signaling Ther. 2021; PubMed Scopus Google Scholar). remains exists a between Nrf2 and OGG1 in leukemia cells. we to that OGG1 promoter the of that Nrf2 could enhance OGG1 expression by directly to its promoter that OGG1 inhibitors can the between OGG1 and the repair effect of OGG1 on cells T. OGG1 inhibitor TH5487 OGG1 chromatin and 2020; 10: PubMed Scopus Google Scholar, T. A. W. G. et inhibitor of OGG1 gene expression and PubMed Scopus Google Scholar). Based on the and could be that OGG1 might be the key factor of drug resistance in AML cells. 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Y. is a inhibitor to overcome resistance in AML cells by with signaling Oncol. 2021; PubMed Scopus Google Scholar). remains Nrf2 regulates the expression of OGG1 and mediates AML resistance AKT signaling Therefore, this study the of and AKT signaling on leukemia cells. The that of Nrf2 the apoptotic by activating AKT After with AKT pathway inhibitor was found that the activity of OGG1 and the expression of the inhibition of AKT pathway could the function of Nrf2–OGG1 was found that the of Nrf2 and OGG1 the inhibition of AKT signaling pathway, which the function of Nrf2–OGG1 is that the activation of AKT pathway could increase the of Nrf2 and which mediates the drug resistance of have also that the activation of AKT signaling pathway can the increase of OGG1 expression Lee DNA damage by the DNA repair Biol. PubMed Scopus Google Scholar, Lee et base in DNA induction of the repair DNA PubMed Scopus (13) Google Scholar). has that by high AKT pathway to the expression of OGG1 S. Y. 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